Self-closing, gravity actuated taps are well-known in the field of fluid dispensers. Gravity-actuated taps often have a conical valve or ball valve, for example with a metal-to-metal seat. In order for the valve to function effectively, the taps must be installed substantially vertically. The taps may be spring actuated self-closing water taps with time delays, for example the spring loaded self-closing water tap in PCT Publication WO 95/33153.
U.S. Pat. No. 7,975,980 to Gao et al. describes an adjustable time-controlled water valve. A time-control apparatus includes an elastomer and a push rod. The elastomer is disposed between a support lid and the push rod. When the push rod is pushed, the water valve is opened. After a certain time, the water pressures are balanced and the elastomer, which has been compressed, will push the push rod back to its initial position to close the valve.
U.S. Pat. No. 5,288,053 to Young describes a discharge controlling device for faucet in which a control lever is used to push a throttle pin axially positioned within the center of the inner sleeve, such that the pin is slidably moved up and down and engages a steel ball to control the opening and closing of a water discharge aperture. As the control lever is pushed by hand and moved from its closed position to the intermediate or open position where the water can be admitted, the steel ball is pushed away from the aperture by the rod tip of the throttle pin. When the control lever is released, the throttle pin falls, and the steel ball, which is subject to water pressure, immediately returns to the position where it closes the aperture. As the control lever is moved manually from its closed position to its open position, the control lever is secured within the locking slot. This locking effect of the slot effectively allows the aperture to remain open after the control lever is released. When the control lever is disengaged from the locking slot, the throttle pin drops and the steel ball, due to the action of water pressure, moves to close the aperture.
Many previous self-closing gravity actuated taps are used in pressurized and centralized water systems. Such self-closing taps are not useful in locations lacking centralized water systems, for example camp sites, hiking trails, and disaster zones. A large number of parts in these taps reduces the taps' reliability and increases their cost. A common problem with many prior art self-closing taps is that they are susceptible to leakage during transport when attached to a fluid source.
Electrical water taps with self-closing valves are extensively used in public washrooms and other facilities to minimize water waste. In addition to their complexity, such water taps require an electrical power source.
Many conventional taps currently used for dispensing water from containers not connected to centralized water distribution systems, do not have self-closing properties. Such taps are often used in locations where water is scarce but do not facilitate efficient water use.
With clean water in increasingly short supply and increased awareness of proper hygiene, there is a need for low cost, efficient water taps which can be used in low-pressure applications and in remote locations. It is, therefore, desirable to provide such a tap.